Various devices are used to control particle, X-ray and gamma ray beams; these devices are based on radiation interference and diffraction, for instance Fresnel microzone plates, multilayer mirrors, and Bragg crystals. Also used for charged particle beam control are magnetic and electrostatic elements. A critical shortcoming of these devices is their narrow spectral band, principally due to the physical phenomena on which they are based.
As is known, incidence of beams of various charged particles, neutrons, X-rays and gamma rays onto boundaries of condensed media, features a certain value of the grazing angle, called the critical angle of total external reflection, below which reflection is accompanied by very low losses. In the case of very smooth surfaces and low radiation absorption in the material of the reflective surface, the losses with total external reflection are so low that they allow efficient beam control via multiple reflections at angles below critical. Known in the art are devices functioning with multiple total external reflection in bent tube channels to concentrate and shape quasi-parallel beams of X-rays (Soviet Physics +Uspekhi, vol. 157, issue 3, Mar., 1989. V. A. Arkad'ev, A. I. Kolomijtsev, M. A. Kumakov, I. Yu, Ponomarev, I. A. Khodeyev, Yu. P. Chertov, I. M. Shakhparonov. "Wideband X-ray Optics With Wide-Angle Aperture", pp. 529-537).
This prior art device for controlling beams of X-ray and gamma quanta, charged particles and neutrons, comprises a plurality of channels with inner surfaces featuring total external reflection, with input butt-ends facing a radiation source, and with output butt-ends directed at a radiation receiver. The channel-forming elements are located on the generatrices of imaginary coaxial barrel-shaped surfaces, and can, for instance, be bent tubes with longitudinal axes positioned along said generatrices.
A shortcoming of this device is the considerable loss in radiation transfer efficiency along the tube channels, due to the inaccuracy of positioning of the tube channels along the generatrices of imaginary barrel-shaped surfaces and non-optimal orientation of the input and output butt-ends at the source and receiver of radiation, respectively. Another shortcoming is the device's relatively narrow spectral band which arises from non-optimal tube channel size. Attempting to optimize such prior art devices involves considerable engineering difficulties, inherent to the positioning of the particular channel-forming elements selected. These restrictions make device assembly a very labor consuming task and, in turn, place restrictions on the minimal channel size and possibility of reducing the beam control device dimensions, restrict the size of the minimal focal area and, thus, the efficiency of concentrating the radiation beam energy.